Visualization systems for building or home automation are used to control and monitor a building or a part of a building, e.g. in functional buildings, hotels, office buildings, hospitals, apartment buildings etc. and display information of the entire building, automation and to control heating, cooling systems, ventilation and air conditioning, systems, lighting, sun-shading systems, fire protection and/or security systems via the building visualization.
Some of the visualization systems use standalone devices running operation system kernel and user interface on the same device. These devices are equipped with a fixed resolution display. The visualization of building or home information is statically designed for this fixed resolution and does not allow resizing to different screen sizes. All views are predefined and composed of controls, text and symbols which perfectly fit to the known screen resolution.
Furthermore, a client/server based architecture is used. In this case the server hosts the system kernel to which one or more remote clients are connected, in order to receive the data for displaying the user interface. Also these known implementations support only clients, which are well known by the system kernel with their fixed screen resolution. Upon request of a known client, the server sends out the predefined screen for the fixed resolution of the client.
Current implementations of building automation visualization systems use browser technologies like HTML, Java Script and style sheets. These technologies give more independence for displaying the user interface on client devices. This technology concept relies on client/server architecture as well. However the client must not be known by the server with its screen resolution. On request, the server only sends a description of the user interface to the client. It is up to the client to read the description and to generate the user interface upon the internal information.
The disadvantages of these implementations concern to the display size and/or resolution of the client, which must be set during commissioning time already. If the client is changed at runtime and the client provides a different display resolution, the user interface will not be displayed correctly. In this case a new configuration and setup is required.
The HTML based implementations are more flexible regarding different clients. But in this case it is not necessary to parameterize the display size of the client beforehand.
However, for generating the visualization of the user interface the client fully relies on a standard software component, called rendering engine, which the operating system of the client provides. The known rendering engines cannot ensure a fully compatible visualization of the user interface on every client display size and resolution. For example the content of a HTTP side is shown too small on high resolution displays.
The rendering engine is provided in order marked up content, such as HTML, XML, image files, etc. and formatting information, such as CSS, XSL, etc., and displays the formatted content on the screen. The content area of a window is displayed on a monitor or a printer.
The rendering engine can integrate e.g. in a web browser, an e-mail, an e-book reader, an on-line help system or another application of the client device, which require the displaying and editing of web content.